Field of the Invention
The invention relates generally to semiconductor device electrical testing and more particularly to apparatus for performing electrical testing on semiconductor devices at various temperatures including elevated temperatures in wafer form.
In semiconductor technology, electronic devices and circuits are made on one semiconductor wafer. They each have various components on them; these components may include transistors, resistors, capacitors, and others. After the circuit has been fabricated, individual components or circuit modules in selected circuits can be probe tested to determine the electrical characteristics of the various components. In the development phase of semiconductors, characteristic tests over a wide temperature range are typically performed in order to test device reliability and performance under temperature stress. Other temperature-dependant tests are performed during production in order to monitor the quantities or presence of certain elements such as mobile ion contaminants that may be introduced during the processing of the material.
Pat. No. 4,567,432 entitled "Apparatus for Testing Integrated Circuits" filed on Jun. 9, 1983 by Buol et al describes a system for testing an integrated circuit die in wafer form at various temperatures. The system involves a resistively-heated wafer chuck which includes a means for heating and/or cooling the wafer via an electrical heating element and refrigerant gas.
While nothing in prior art suggests or teaches the use of a Rapid Thermal Processing chuck or susceptor for probe testing of semiconductors, or the use of such a chuck in or with a probed test fixture, several patents have been issued for the production of semiconductors using Rapid. Thermal Processing. One such patent is U.S. Pat. No. 4,891,499 filed Sep. 9, 1988 by Moslehi, entitled "Method and Apparatus for Real-time Wafer Temperature Uniformity Control and Slip-Free Heating on Lamp Heated Single-wafer Rapid Thermal Processing Systems". Another such patent is U.S. Pat. No. 4,830,700 filed Apr. 27, 1988 by Davis et al entitled "Processing Apparatus and Method" wherein the processing apparatus also utilizes Rapid Thermal Processing. In these Rapid Thermal Processing (RTP) patents the semiconductor wafer is placed either device side down or device side up in a vacuum or atmospheric chamber prior to the processing stages at relatively high temperatures.